18.2.1.2 MySQL Cluster Auto-Installer Overview

The MySQL Cluster Auto-Installer is made up of two components.
The front end is a GUI client implemented as a Web page that
loads and runs in a standard Web browser such as Firefox or
Microsoft Internet Explorer (see
Section 18.2.1.1, “MySQL Cluster Auto-Installer Requirements”). The
back end is a server process (ndb_setup.py)
that runs on the local machine or on another host to which you
have access.

These two components (client and server) communicate with each
other using standard HTTP requests and responses. The back end
can manage MySQL Cluster software programs on any host where the
back end user has granted access. If the MySQL Cluster software
is on a different host, the back end relies on SSH for access,
using the Paramiko library for executing commands remotely (see
Section 18.2.1.1, “MySQL Cluster Auto-Installer Requirements”).

MySQL Cluster Auto-Installer Interface.
This section describes the layout and navigation of the MySQL
Cluster Auto-Installer, whose Welcome screen looks similar to
what is shown here when it is first opened in the Web browser:

You can access the installer UI by selecting either of the
options Create New MySQL
Cluster or Continue Previous
Cluster Configuration. A typical screen in the
Auto-Installer includes the following elements:

Display panel.
The central area where data regarding configuration
settings and controls for changing them are displayed.

Breadcrumb navigation.
Located in the top left and top center of the GUI, the
breadcrumb navigation bar consists of a series of titles
linking to screens that correspond to steps in the
configuration of a MySQL Cluster. The breadcrumb allows
you to jump between these stages in arbritrary order.

Sequential navigation.
This consists of a set of buttons labelled
Previous,
Next, and
Finished, and can be found in the
lower right-hand corner of the GUI. The sequential
navigation is used to move between steps in the suggested
order.

Settings and Help menus.
These menus can be found in the top right corner of the
GUI (to the right of the breadcrumb navigation bar).
Settings provides a way check and
possibly alter configuration settings for the
Auto-Installer; Help can be used to
access the installer's built-in help files.

The locations of the elements just described are shown here in a
typical page in the Auto-Installer; the numbers superimposed
thereupon correspond to those used in the preceding list.

All of these elements except for the display panel are described
in greater detail in the remainder of this section.
Section 18.2.1.3, “Using the MySQL Cluster Auto-Installer”, describes
the panels shown in the display area as well as the
functionality of each panel and the controls it contains.

Arbitrary and sequential navigation.
The Auto-Installer can display any of a number of pages
covering different stages in the setup and configuration of a
MySQL Cluster deployment. You can navigate between pages in
either of two ways. The first of these is the breadcrumb trail
navigation toolbar displaying the titles of the various pages
(in which the title of the current page is highlighted and
disabled). From these, any desired page, in any desired order,
can be reached by selecting the title of the corresponding
page. This toolbar is shown here:

The second navigation mechanism provided by the Auto-Installer
consists of the Next,
Previous, and
Finish sequential navigation buttons at
the bottom right of the page. These can be used to move to the
next or previous page in predetermined order, or to go to the
very last page. The buttons are enabled and disabled as needed,
so that you cannot, for example, advance beyond the last page.

Settings and Help menus.
These menus are positioned adjacent to one another in the top
right corner of the GUI, as shown earlier in this section. The
Settings menu is shown here in more detail:

The entries in the Settings menu are
described here, in the following list:

Clear configuration and restart:
Remove all hosts and processes; reset all parameter values
to their defaults; start the installer over at the first
page.

Automatically save configuration as
cookies: Save your configuration
information—such as host names, process data, and
parameter values—as a cookie in the browser. When this
option is chosen, all information except any SSH password is
saved. This means that you can quit and restart the browser,
and continue working on the same configuration from where
you left off at the end of the previous session).

Since the SSH password is never saved, you must supply this
once again at the beginning of a new session, if one is
used.

Show advanced configuration
options: Show advanced configuration
parameters in the Auto-Installer and make these settable by
the user.

Once set, the advanced parameters continue to be used in the
configuration file until they are explicitly changed or
reset. This is regardless of whether the advanced parameters
are currently visible in the installer; in other words,
disabling the menu item does not reset the values of any of
these parameters.

Automatically get resource information for new
hosts: Query new hosts automatically for
hardware resource information to pre-populate a number of
configuration options and values. In this case, the
suggested values are not mandatory, but they are used unless
explicitly changed using the appropriate editing options in
the installer.

As with the installer's navigation elements, one or more of
the entries in the Settings menu may be
disabled due to choices you have made previously.

The Help menu is shown here, as it appears
when expanded:

The Help menu provides several options,
described in the following list:

Content: Show the built-in user
guide. This is opened in a separate browser window, so that
it can be used simultaneously with the installer without
interrupting workflow.

Current page: Open the built-in user
guide to the section describing the page currently displayed
in the installer.

About: This will show a small dialog
displaying the installer name and the version number of the
MySQL Cluster distribution it was supplied with, similar to
what is shown here:

The Auto-Installer also provides context-sensitive help in the
form of tooltips for most input widgets. One of these tooltips
is displayed when the mouse hovers over a widget or the small
question mark which can sometimes appear next to a widget label.

In addition, the names of MySQL Cluster configuration parameters
are linked to their descriptions in the online MySQL Cluster
documentation, so that if you click on the name of a given
parameter, the documentation for that parameter is shown in a
separate window.